If these blobs are being caused by a sudden temperature inversion:

1) How did they appear over several midwestern cities at the same time?

2)Why have some of them lasted for hours?

If these are caused by sudden changes in temperature, it would follow that the effect would be temporary and that it wouldn't simultaneously appear in several cities that are over 100 miles apart (in some cases).

On the first night of this effect there were several cities that were affected at once (for those who have only seen the recent images and may have missed what was going on as I started the thread). I don't see how radars in Chicago, Des Moines, Lansing, and Duluth (and other places) could all be tripped up by a temperature change at the same time. That would seem to imply that there was a near instantaneous temperature change across the midwest that caused the exact same error throughout it. Ok... so maybe the upper atmosphere can undergo such a radical change... so why weren't the Canadian radars affected?

BTW, the ground conditions were constant during all this last night... and I was having the same problems with my tv before going on the internet an hour ago.

..but maybe I just happened to have a weird problem with my tube at the same time a weird radar screwup is going on?

BTW,
I don't mean to keep pushing an 'unscientific' thread. I do, however, feel that the 'definite' causes some people have mentioned need to be examined further. Why? Because we've already had a situation where the experts have come up, in turn, with three 'definte' reasons for why these blobs are showing up. So we've heard that these are being seen because of 1) a change in radar mode, 2) Ground clutter, 3) Temperature inversions.

It seems like all three can't be correct at the same time, and if some are wrong than the expert dismissal of these things needs to be questioned a little.

If these blobs are being caused by a sudden temperature inversion:
1) How did they appear over several midwestern cities at the same time?

The temperatures are dropping as nightfall approaches in all the cities. If you constantly monitor all the sites you'll see they don't really appear at the exact same time, but appear further east and then move west as the sun sets, temperatures decrease, and temeprature inversions form.

2)Why have some of them lasted for hours?

There is nothing surprising about them lasting for hours. All it takes is a large difference in temperature between two levels of atmosphere. This situation can certainly exist for hours.

If these are caused by sudden changes in temperature, it would follow that the effect would be temporary and that it wouldn't simultaneously appear in several cities that are over 100 miles apart (in some cases).

Sorry, by "sudden" I mean that if it's 80 degrees on the ground, 78 degrees at 1000 feet, and 70 degrees at 2000 feet, you have a sudden temperature change between 1000 and 2000 feet. I didn't mean "sudden" in that the temperature necessarily changes suddenly over time. I meant over altitude.

On the first night of this effect there were several cities that were affected at once (for those who have only seen the recent images and may have missed what was going on as I started the thread). I don't see how radars in Chicago, Des Moines, Lansing, and Duluth (and other places) could all be tripped up by a temperature change at the same time. That would seem to imply that there was a near instantaneous temperature change across the midwest that caused the exact same error throughout it.

Why not? All those cities are pretty close to the same longitude which means they're all going to start seeing temperature changes from the sun at about the same time. When the sun is going down in Des Moines, it's also going down in Duluth and has just set a few minutes before in Chicago and Lansing.

Ok... so maybe the upper atmosphere can undergo such a radical change... so why weren't the Canadian radars affected?

The Canadian radars may have different software that has better or different filters to remove anomalous propagation. Or the Canadian radars may be in a lower sensitivity mode. AP is generally only observed when the radars are in ultra-sensitive ("clear air") mode. That's the sensitive mode where the radar can and does return birds, insects, dust, and is very susceptible to anomalous propagation.

BTW, the ground conditions were constant during all this last night...

It's not the ground conditions that cause these echos, it's the atmospheric conditions from a few thousand feet up (close to the radar) to 50,000 feet up hundreds of miles away. And the conditions which cause these echos are invisible temperature differences, not visible clouds. So you're certainly not going to see anything by looking up at the sky.

and I was having the same problems with my tv before going on the internet an hour ago.

Buy a new TV, get a better antenna, or call your cable company for service.

..but maybe I just happened to have a weird problem with my tube at the same time a weird radar screwup is going on?

Exactly!

Hey,

Thanks for those answers.

I don't mean to keep pushing an 'unscientific' thread. I do, however, feel that the 'definite' causes some people have mentioned need to be examined further. Why? Because we've already had a situation where the experts have come up, in turn, with three 'definte' reasons for why these blobs are showing up. So we've heard that these are being seen because of 1) a change in radar mode, 2) Ground clutter, 3) Temperature inversions.

A change in radar mode will cause temperature inversions to be visible on radar that wouldn't otherwise be visible. So #1 and #3 are really the same thing. The only disagreement would be whether it's ground clutter or temperature inversions. Ground clutter is often used as a general term to refer to any "blob" around a radar site that isn't real weather. That term is thrown around a lot in general.

Specifically, ground clutter is caused by structures that are relatively close to the radar (within about 25 miles) which literally cause an echo back to the radar under normal operating conditions due to the sidelobe radiation from the radar. Sidelobe radiation is due to the fact that the radar's radio frequency beam isn't perfectly focused like a laser. This means that some minimal amount of the radar energy will hit structures below the beam that are relatively close to the radar. This minimal energy then bounces back and is often received as a radar return. Ground clutter is a very severe problem with radars and each NEXRAD has its own ground clutter removal logic which essentially maps the local ground clutter so that it can be "subtracted" from radar images in the future. If NEXRAD didn't have ground clutter removal logic the images you see online would be quite useless and would always have a blob around them.

The good thing about ground clutter is that it is fairly constant which means it can be mapped and later subtracted from future radar scans.

Anomalous propagation, as I already said, is caused by differences in temperature in the atmosphere which literally bend the radar beam down to the ground. The ground then reflects the energy back to the radar (or back up to the atmosphere which may reflect it back to the radar). AP isn't constant like normal ground clutter, though, so it's extremely difficult to filter out AP. But anomalous propagation is a type of ground clutter. It's just ground clutter that normally doesn't exist because it occurs so far away from the radar.

It seems like all three can't be correct at the same time, and if some are wrong than the expert dismissal of these things needs to be questioned a little.

As you can now see, yes, all three explanations are valid.

It made me wonder if government was playing their HAARP again, another experiment or the real thing this time?

No, unless the government has a symphony orchestra that includes a harp.

Are these blobs like an experimental shield for cities they want to protect from a bio attack?

No.

Could a sheild of overcast skies protect us?

No.

Or atleast protect the cities they choose?

Right. Of all the cities in the country they could protect I can see why Duluth was right up there at the top of their list.

[off topic]
Posted on page 4 of this thread:

Originally posted by everlastingnoitall
You know, yesterday I think I actually saw my first chemtrail. I was travelling east on US HWY 20 in Iowa, there were very high altitude, whispy clouds in the air. At an almost stratospheric altitude, a jet of some sort flew through the clouds, leaving a trail, of course. I watched the trail for several minutes, and as I did, I noticed the clouds getting thicker and spreading almost immediately. There also appeared to be a darker, 'heavier' material seperating and distributing itself from the original trail until it became a trail of its own, and widened and eventually dispersed. Any clues if this had something to do with this? Anyone else see any chemtrails yesterday? (emphasis added by Bangin)

E_T, since you posted those pictures I thought that I'd ask you to explain why the above member saw what he did. Specifically, I'm interested in the bold print. I'd like your thoughts on the subject before I ask a rabid member, who shall remain anonymous ( ) , to explain why this happens occasionally.

[edit on 9/26/2004 by Bangin]

Originally posted by antipigopolist

You just don't understand. Nice try though.
The link from the intitial post is in clear air mode. I never stated anything in regards to any follow-up link posted by others.

So...for the reading impaired...

Yes. I get your point, but also for the reading impared, I’ll restate a piece of my post:

Originally posted by defcon5

Only the chicago site reads as being set to Clear Air mode.

Dotgov101 every one of the screen shots that you are showing state on them that they are in CLEAR AIR MODE.


Now for those of you that did not see what was happening that night, let me more clearly explain it. I checked on Multiple Radar sites across the country. I listed only a few in my earlier post. All the sites seemed to coincide that there was something weird going on from Michigan to the Dakota’s, down to Arkansas and over to Texas. There where these blobs that would appear and disappear repeatedly and rapidly. The clouds over the eastern US, out west, and down in Florida all looked normal, but the rest looked like popcorn that was being popped. 90% of those radar’s clearly stated on them that they where in PRECIPITAION MODE. Now the temperature inversion thing I might buy, if you can tell me that it is possible for that to occur over that large an area for hours. As far as it being ground clutter, NO WAY, I’ve seen ground clutter, and it does not extend out that distance from the radar ever, it also does not rotate like a hurricane around the radar.


Oh, and just so you know how impartial that my judgment is on this, I don’t believe in the Chemtrail stuff, and really doubt the acclaimed powers of HAARP. Now, I am not saying these things might not exist, or could not, simply that I am not tipping this balance to point in the conspiracy direction because I am pushing some belief I have.

defcon5,
Good point about the rotation. Yes... it was rotating.

And thanks, also, for the summary of the night. I wish that I had written a better initial thread... but I was trying to notify people before the effect began to vanish.

Indeed, these blobs were appearing and dissapearing over several cities. Like I said before, one appeared to 'jump' from Minneapolis to Duluth (which would mean that the 'inversion' -- if it was an inversion -- travelled eastward).

In general, it might be a good idea for everyone to keep a close eye on those radar images. The next time this happens we may be able to keep a better track of the events and be able to decide if it was an inversion issue.

You know,

If I had come to this thread late -- let's say I logged on the morning afterwards -- I would think that we were a bunch of nuts who were intent on ignoring everything the experts have said....

...all because we had no way of storing a loop of what was going on that night.

But, yes Defcon, tonight isn't the same as a few days ago. The returns aren't doing the same things in all the markets. I just wish I knew how to save and store the loops from a few days ago.

Since they are a loop of scrolling pictures, I don’t think that it is possible to do. If there is anyone out there that knows how, I would be interested to know…

Thanks,

I know that you think I am nuts, but I read your stuff, and even you had me convinced, until I read that they where on Precip.

Maybe something similar will happen, or maybe its something else, and if we can get the actual pictures, you guy that know more about it can figure out exactly what it was.

They've been identified!!!



Seriously though, this really is odd.... Good find!

No conspiracy here... local doppler radars always have static near its tower. This static usually appears as a "blob" indicating rain where there usually is none; this static usually appears circular in shape (since the radar waves go out from the tower's top in a spherical shape), but it can look different depending on the cloud cover over the tower's immediate area. Basically, it's the radar version of the feedback you get when your microphone is too close to the speaker (both cases are electromagnetic phenomenon).

Usually, doppler radar stations try to edit out this static area in their radar pictures, since they know that it's due to false echoes. However, sometimes they forget, or simply don't need to if it really is raining over the tower's immediate area. Also, some weather radar websites now simply give you the raw data, static area and all.